How To Tell If You're Lifting Too Light In The Gym

When you first start out in the gym, shifting tin can be hard work. But as your body adjusts to the load, you'll soon find it becomes easier and easier to lift that same weight.

So how do you know if you're lifting too light in the gym? Thankfully, scientists actually have an answer.

According to new findings published in the European Journal of Sport Science, anything below 20 per cent of your one rep max (1RM) will not add muscle while it's recommended that you perform with at least 40 per cent 1RM.

To come up with their conclusion, researchers orchestrated a randomised study where volunteers either performed at 40 per cent, 60 per cent or 80 per cent of their 1RM. They also had the group with the heavier load exercise at 20 per cent 1RM.

Results suggested similar hypertrophy for those who performed 40 per cent, 60 per cent or 80 per cent of their 1RM. However, those performing at 20 per cent experienced significantly less growth.

"It is now well-established that lifting relatively light weights can substantially increase muscle development. However, the question arises as to whether there is minimum threshold below which growth is compromised," study author, PhD holder and fitness coach Brad Schoenfeld wrote on his Instagram.

"Our study set out to determine if such a threshold exists. As shown in the infographic, a load equating to 20 per cent 1RM was suboptimal for eliciting a hypertrophic response compared to loads >40 per cent."

It is now well-established that lifting relatively light weights can substantially increase muscle development. However, the question arises as to whether there is minimum threshold below which growth is compromised. Our study set out to determine if such a threshold exists. As shown in the infographic, a load equating to 20% 1RM was suboptimal for eliciting a hypertrophic response compared to loads >40%. ⁣ ⁣ A caveat to the findings is that we equated volume load between conditions. Since the lowest load condition performed a lot more repetitions to reach failure, we thus had to add more sets to the heavier load conditions to equate the total work performed; although somewhat speculative, it is likely that hypertrophy would have been more similar across conditions if the sets were equated as opposed to volume load. It also is important to note that subjects were untrained; thus, we cannot necessarily generalize findings to those with extensive resistance training experience. ⁣ ⁣ Bottom line: The evidence indicates that yes, you can go too light when the goal is muscle-building, and the approximate amount is estimated to be ~20% 1RM. You can download the study on my Researchgate page. 💪🏽 #gainz

However, there's a catch. Since the lower weight included more repetitions, the heavier weight was performed with more sets to make up for the lesser repetitions.

"A caveat to the findings is that we equated volume load between conditions. Since the lowest load condition performed a lot more repetitions to reach failure, we thus had to add more sets to the heavier load conditions to equate the total work performed; although somewhat speculative, it is likely that hypertrophy would have been more similar across conditions if the sets were equated as opposed to volume load," Schoenfeld continues.

"It also is important to note that subjects were untrained; thus, we cannot necessarily generalise findings to those with extensive resistance training experience.

"Bottom line: The evidence indicates that yes, you can go too light when the goal is muscle-building, and the approximate amount is estimated to be ~20 per cent 1RM."

While hypertrophy training is great for getting jacked, if you want to build lean muscle, diet is equally if not more important. Here are eight carbs that should be in your diet if you want to pack on muscle.

Alex PierottiA one-time third-grade try-scorer, Men's Health's Digital Content Editor, Alex Pierotti, is obsessed with two things: the beach and his footy team. When he’s not researching the latest studies, figuring out the latest style trends or snacking on cashews you'll find Alex cruising on his board through Bondi Beach